Liverpool lead new tactical era of 'storming' while the likes of Mourinho are left behind

Football is changing before our eyes as a new tactical era takes hold. David Merrell

Top-class football is changing before our eyes. Liverpool's 5-2 rout of Roma in the first leg of their Champions League semifinal merely confirmed it. The game is moving into a new tactical era: Attacking pressing is becoming so rapid that it should probably be called "storming."

That is why we are seeing so many big wins in big games. And it's also why we're seeing managers such as Jose Mourinho struggling to adjust (more on that below).

Liverpool are only the most obvious practitioners of storming. Gegenpressing -- as the Germans call the style -- means chasing up the opposition's defence the moment you lose possession, in order to win the ball near their goal. "Gegenpressing is the best playmaker in the world," Jurgen Klopp likes to say. When it works, a storming team can rack up the goals.

You see this trend even in matches between two world-class teams. When Germany put seven past Brazil at the 2014 World Cup, we thought this was a one-off. In fact, it was an only slightly exaggerated portent of what has come since. Consider the blowout wins in Champions League knockout games in the past two seasons:

2016-17 stats courtesy of ESPN Stats & Information. ESPN SIG

The three results from this season's round of 16 can be explained in part by the financial divide in modern football: a big club thrashed a smaller one. However, in each case, the big club spent long periods storming the small club's goal, instead of the old method of sitting back after taking a comfortable lead:

2017-18 stats courtesy of ESPN Stats & Information. ESPN SIG

And if you think this is a big theory built on a small sample of games, here is more evidence of the trend:

- This is already the highest-scoring Champions League season ever, with 387 goals in 122 games so far, or 3.17 per game. The previous record season was 2016-17.
- As Jonathan Wilson has noted in The Guardian, the number of big wins -- by three goals or more -- in the quarterfinals and later has risen sharply over the past eight seasons, compared with the previous eight.
- UEFA's own report on the most recent Champions League season found that the average goal was scored "after an average of 10.62 seconds of ball possession." That was 8 percent less pre-goal possession time than just two years before, in 2014-15. This looks like evidence, says UEFA, of "a trend towards more direct attacking".
- The Premier League is also becoming more goal-rich. In the 1992-2009 period, average goals per game over a season were below 2.7 in every season but one (in 1999-2000, when it hit 2.8). Since 2009-10, average goals have been above 2.7 in every season except one.

So what is going on?

Pressing isn't totally new. In the 1970s, it was used by teams as different as Leeds and Holland, who called it jagen, or "hunting." German teams, helped by their superior fitness, would often raise the pace of play and send defenders and midfielders pelting forward for brief spells, usually immediately after the opposition had taken the lead.

At the 1986 World Cup, the Soviet Union pioneered an early form of storming in a 6-0 demolition of Hungary. They would attack for a minute or two at an insane pace, score, then rest for a while by passing around quietly in defense. Taking breaks was a necessity in an era in which players were not particularly fit and especially in the heat of the Mexican World Cup.

But modern players are fit enough to storm often and at unprecedented pace. High-intensity running has increased by 50 percent in the Premier League over the past decade, according to a study led by the University of Gothenburg last year which read, in part:

Compared with in the past, modern top-class soccer is characterized by more high-intensity sprints followed by a substantially lower tempo. Repeated bouts of high-intensity running for 1-5 minutes are followed by a historically low intensity for up to 5 minutes. Thus, a player's activity level during a match tends to alternate between two extremes, compared with the traditionally more steady match tempo.

In storming teams, wing-backs and full-backs pelt forward into attack. Some teams compensate by fielding three central defenders. The midfield's job is to win the ball high up and immediately feed the forwards.

That is why Liverpool's James Milner, a ball winner rather than a creator, leads the Champions League in assists this season; think of the loose ball he won in the 3-0 drubbing of Manchester City to set up Alex Oxlade-Chamberlain's long-range strike.

Storming teams also have a stunningly attacking mindset. Even after they have scored a couple, they try to keep storming. Brazil vs. Germany in 2014 was the original case-study, but Liverpool did the same against Roma. You might say this is a risky strategy and, indeed, Liverpool got tired and conceded two late goals.

Storming teams are often undermanned in defense and can be overrun by others playing similarly. That happened to Roma's three-man defense at Anfield. They didn't perform any sort of effective pressing for most of the game -- gegen or otherwise -- but their manager Eusebio Di Francesco had previously impressed with his attacking philosophy and an even higher defensive line than that of Klopp.

Liverpool's playing style has led them to the brink of the Champions League final. EPA/Peter Powell

Liverpool have also had doses of their own medicine: Recall that in the league this season they lost 5-0 at Man City and conceded three times at home to the same opponents, while scoring four themselves. Defensive teams are rarely so vulnerable.

But you could also say that if storming has brought you a couple of early goals, it's clearly working, so why switch tactics if you're not tired? By contrast, if you go 2-0 up and "park the bus," your opponents only need to nick a goal to be back in the tie. If you think you can outscore them by continuing to storm, then that is the safer bet.

Also, a good storm can send opposing teams into a panic and their positioning sometimes goes to pieces. Brazil, in their 7-1 loss to Germany, were the perfect example, but think also of PSG during Barcelona's remontada last year, or of teams as defensively strong as Juventus and Real Madrid during their two quarterfinal encounters this season. All of these teams are used to having the ball, so they get confused when the opposition keeps taking it away in their own half.

The teams that have embraced storming most enthusiastically are those which, on paper, look just short of top-class; think of Roma, Napoli and even Liverpool. Leaving aside Mohamed Salah, none of their players would get into a World XI and Klopp's team can't win the Champions League by building patiently from the back, so they major on fitness -- perhaps no other club trains harder -- on pace and on their complex pressing tactics.

By contrast, the most skilful teams build more slowly. Barcelona are the extreme example, but Real Madrid also spends more time on forming attacks than speed-merchants Atletico, while Bayern in possession advance the ball the fewest metres per second of any team in the Bundesliga, according to Opta Sports analytics.

Still, Bayern and Real also use elements of storming football. Think especially of their attacking full-backs: In last Wednesday's semifinal first leg between the two teams, Joshua Kimmich and Marcelo each scored their third goal in this Champions League season (Kimmich in 10 games, Marcelo in nine).

One oddity of storming is that it tends to work best against the most skilful teams. It's hard against defensive sides that keep 10 men back, which explains how Liverpool could lose 2-1 at home to Wolves in last season's FA Cup. It's also hard to storm a long-ball team, because they will just go long by way of bypassing.

But teams that try to pass the ball out from defense are vulnerable, which might explain Barcelona's three big defeats in 14 months to PSG, Juve and Roma. Moreover, skilful teams often have defenders, who are chosen more for their offensive qualities -- think David Luiz or John Stones -- and these players can struggle in a storm.

Whenever a new trend emerges, established tacticians have to decide whether to go along with it. Pep Guardiola has embraced storming at Manchester City. He comes from a tradition of pressing, albeit of a less frantic variety: his Barcelona teams aimed to win back the ball within five seconds of losing it, even if in possession they would build quite leisurely. Later at Bayern, he imbibed some of the German tradition of pace and overlaps.

But Jose Mourinho seems to have been left behind by the storming trend. For most of his career, except at Real Madrid where his team set a Liga record for goals in 2011-12, he has usually aimed to win games 1-0. The defensive approach sounds safe but can be high-risk: If you don't send many players forward, you may not score and the opposition can nick a goal from a rare attack; remember Manchester United's recent 1-0 home defeat to West Brom.

United are now 16 points behind City in the Premier League, despite having conceded only one goal more. The difference between the two sides is that City have scored 98 goals which, over 34 matches, is very nearly a goal a game better than United's 65.

Mourinho, by asking his defensive players to sit back in a wall, isn't using the physical capacities of the modern player to the full. As of January, United had run fewer yards than any other team in the Premier League.

But he shouldn't feel too bad about getting left behind; that's the ultimate fate of most innovators. It happened to Arsene Wenger a decade ago and, one day, it will happen to Klopp too.